In large filter/separator installations subjected to vibration such as in marine applications and in mobile and static installation also subject to vibration it is proposed to mount replaceable fuel or lubricating oil filter cartridges on screw-mounting and connecting parts provided within a cylindrical enclosure whereby fluid can flow radially inwardly or outwardly through a generally cylindrical filter element the interior and exterior of which are mutually sealed for fluid flow except through the filter element itself. In such an installation it is important to ensure that vibration does not result in loosening of the filter cartridge on its screw base since such loosening can result in a seal between the interior and the exterior of the element being bypassed by flow other than through the element itself. The present invention seeks to prevent such loosening even in cases where a mounting spigot with a screw thread is formed of relatively soft material such as moulded plastics.
According to the present invention there is provided an assembly of conjoined parts comprising a mounting part and a mountable part said parts having complimentary means operable to conjoin them by relative rotation of the parts wherein one said part is provided with at least one resiliently deflectable locating member engageable with a locating track of the other part to resist relative rotation.
In a preferred embodiment of the invention the second mountable part carries the locating member and the mounting part carries the locating track the locating track extending arcuately around and concentric with a screw-threaded portion such that upon screwing the parts together the locating member moves increasingly into engagement with the track.
The locating track may be arranged to extend in an axial direction such that substantial engagement between the locating member and the track is maintained over a range of relative axial positions of the parts or it may be arranged to extend radially to be met by axial movement of the locating member.